The strain Clostridium beijerinckii CCM 6218 has been selected as the best solvent producer from a group of six tested clostridial strains with respect to the results achieved using sugar beet molasses and juice cultivation media. The bioreactor cultivation with this strain and cultivation medium containing sugar beet juice lead to butanol yield 26% and productivity 0.28 g.l-1.h-1 what were values completely comparable with published data summarizing results obtained with use of different saccharidic substrates. Thus, sugar beet juice proved to be a superior substrate for biobutanol production.

Production of ethanol from lignocellulose biomass has attracted wide attention in recent decades. Despite its undeniable advantages (low price, renewable source) there are also some problems such as formation of inhibitors in lignocellulose pre-treatment process. The inhibitors can influence not only the efficiency of enzymatic hydrolysis of cellulose but also the metabolism of microorganisms producing ethanol. Toxic effect of selected inhibitors on growth of Saccharomyces cerevisiae, Pichia stipitis and Zymomonas mobilis decreased in the order of furfural → hydroxymethylfurfural → 4-hydroxybenzoic acid. While S. cerevisiae was quite resistant to all tested inhibitors, growth of Z.mobilis was highly influenced by furfural. Contrary to other strains, P. pastoris was sensitive to the presence of 4-hydroxybenzoic acid. These results indicate that a careful selection of microorganism less sensitive to inhibitors can improve the productivity of lignocellulose ethanol.